Transparent flexible film



35 ture of films intended such for example as zein derived from corn tion or sacrificing allot its material advantages. 40

' 45 able-plasticizer, such for example as di-butyl wrapping of packages and, for other uses, which 45 55 zein and 90% alcohol water solvent. Preferably" comprises a fixed zein base, 'a plasticizing quan- 55 Patented Mar. 2 3193) I Q H UNITED 'STATES' PATENT OFFICE TRANSPARENT FLEXIBLE FIIM Donald W. Hansen, Decatur, Ill., assignor, by

. mesne assignments, to Prolamine Products Incorporated, Dover, Dei., a corporation of Delaware A No Drawing. Application February 29, 1992 Serial No. 595,960

4 Claims. (01. 18-57 This invention relates to transparent films this solution is first concentrated to bring the adapted for. the wrapping of packages and for percentage ofzeinup to about 20% of this conother uses such for example as coatings upon centrated solution. We preferably add to this various articles, cartons, paper sheets, etc., and solution a plasticizer which is compatible with 5 has for its object broadly the provision of an imthe zein in the alcohol water solvent, such as 5- proved film which may be produced economically di-butyl phthalate.

and through the use of ingredients generally The resulting compound is then run over or available in large quantities and obtainable at onto a suitable sheeting or filming surface and 'low costs. the solvent evaporated to produce the desired The invention has for further important fiim,thereafter the film or sheet is or may be 10 object the provision of a film of the character fixed with some suitable tanning agent preferably described which may be easily she'eted and which an aldehyde as formaldehyde. by simple changes in the formulae and in the A typical formula is or may be 1% of di-butyl steps of the process of manufacturing the product phthalate of the 20% solution of zein. In addi- 5 may be given varied characteristics adapted to tion to the di-butyl phthalate plasticizing agent meet particular and intended needs. and the zein, it is often desirable to add a quan- The invention contemplates the production of tity of glucose up to 10% and higher to the solua transparent flexible film of improved char-' tion before final drying. acteristi'c which may be produced mainly from After the compoundhas been evaporated upon 0 vegetable materials and inthis regard contemthe filming or sheeting surface to coherency and plates the production of such a film from a suitapreferably before complete drying is accombly treated vegetable protein. v plished it is treated with a tanning agent either A further and separate object of the invention in liquid form or gaseous form. is the provision of a flexible transparent film of In order to insure that the film does not be- 5 the character described which may be manucome cloudy in the sheeting and final drying we f actured economically from Indian corn with or prefer to incorporate about 2% to the 20% zein without added plastieizingand fixing materials solution of tri-ethanolamine in the solution. and/or with or without materials added to 9.0- Since the materials do not have a tendency to complish water or moisture proofing. devitalize at relatively high-temperatures when Another important object of the invention is wet and since the solvents employed are largely the provision of a'composition for the forming alcohols quick drying at relatively high temperaof a film of the character described which may ture is or may be accomplished. be more easily and more quickly dried than has It is thought that the invention and many of heretofore appeared practical in the manufacits attendant advantages will be understood from to fulfill the purposes of the foregoing without further description and it the film of this invention. will be apparent that various changes may be In accordance with the present invention the made in the ingredients, in their proportions,

film is preferably mainly composed of a vegetable and in the steps of producing the film without protein. The protein is or may be a prolamin departing from the spirit or scope of the invengluten. Theprotein is preferably and for most The form hereinbei'ore described being merely a intended uses of the 'film fixed with some tanpreferred embodiment thereof. 1

ning agent as formaldehyde and the invention We claim:

contemplates the use when desired of a suit- 1. A transparent flexible film adapted for the phthalate. e comprises a fixed prolamin and di-butyl phthal- The zein is extracted from corn gluten by disate as a plastizer, and a transparentlzing quansolvlng'it in a mixture of alcohols and some tity of tri-ethanolamine.

water. Since this processofextraeting zein from 2. A transparent flexible film adapted for the gluten forms no part of the present invention wrapping of packages, which comprises a fixed 50 particular description of such extraction will not prolamin having admixed therewith a plasticizhere be undertaken. As the result of such 'exing quantity of di-butyl phthalate, and glucose.

traction an alcohol Water solution of zein is pro- 3. A transparent fiexible film adapted for the duced consisting typically ofapproximately 10% wrapping of packages and for other uses, which tity of d1-buty1phtha1ate,and a transparentizing being variable from 1 part to every 20 parts of quantity of tri-ethanolamlne. zein, and e, transparentizing quantity of tri- 4. A transparent flexible film adapted for the ethanolamine, said tri-ethanolamlne being variawrapping of packages and for other uses which ble from 2 parts to very 20 parts of zen 5 comprises a fixed zein base, a plasticizing quantity of dl-butyl phthalate, said di-butyl phthalate DONALD W. HANSEN. 

